Chlorophyll Concentration#
Figure. Change in Chlorophyll from satellite. The map (top) shows the change in annual mean Chlorophyll-a concentration (mg/m3) in the vicinity of Palau over the period 1998-2024 derived from satellite remotely sensed ocean color data. The grey line is the Palau EEZ. The line plot (bottom) shows the change in mean Chlorophyll-a concentration (mg/m3) averaged over the area within the top plot. The black line represents the trend, which is not statistically significant (p < 0.05).
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import warnings
warnings.filterwarnings("ignore")
import os
import os.path as op
import sys
import pandas as pd
import numpy as np
import xarray as xr
import geopandas as gpd
import cartopy.crs as ccrs
import matplotlib.pyplot as plt
from myst_nb import glue
sys.path.append("../../../../indicators_setup")
from ind_setup.plotting_int import plot_timeseries_interactive, plot_oni_index_th
from ind_setup.plotting import plot_base_map, plot_map_subplots, add_oni_cat, plot_bar_probs, fontsize
sys.path.append("../../../functions")
from data_downloaders import download_ERDDAP_data, download_oni_index
Setup#
Define area of interest
#Area of interest
lon_range = [129.4088, 137.0541]
lat_range = [1.5214, 11.6587]
EEZ shapefile
shp_f = op.join(os.getcwd(), '..', '..','..', 'data/Palau_EEZ/pw_eez_pol_april2022.shp')
shp_eez = gpd.read_file(shp_f)
Download Data#
update_data = False
path_data = "../../../data"
path_figs = "../../../matrix_cc/figures"
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base_url = 'https://oceanwatch.pifsc.noaa.gov/erddap/griddap/esa-cci-chla-monthly-v6-0.csv'
dataset_id = 'chlor_a'
if update_data:
date_ini = '1998-01-01T00:00:00Z'
date_end = '2024-12-01T00:00:00Z'
data = download_ERDDAP_data(base_url, dataset_id, date_ini, date_end, lon_range, lat_range)
data_xr = data.set_index(['latitude', 'longitude', 'time']).to_xarray()
data_xr['time'] = pd.to_datetime(data_xr.time)
data_xr = data_xr.coarsen(longitude=2, latitude=2, boundary = 'pad').mean()
data_xr.to_netcdf(op.join(path_data, f'griddap_{dataset_id}.nc'))
else:
data_xr = xr.open_dataset(op.join(path_data, f'griddap_{dataset_id}.nc'))
Analysis#
Average#
fig, ax = plot_base_map(shp_eez = shp_eez, figsize = [10, 6])
im = ax.pcolor(data_xr.longitude, data_xr.latitude, data_xr.mean(dim='time')[dataset_id], transform=ccrs.PlateCarree(),
cmap = 'Greens', vmin = np.percentile(data_xr.mean(dim = 'time')[dataset_id], 1),
vmax = np.percentile(data_xr.mean(dim = 'time')[dataset_id], 99))
ax.set_extent([lon_range[0], lon_range[1], lat_range[0], lat_range[1]], crs=ccrs.PlateCarree())
plt.colorbar(im, ax=ax, label='chlorophyll (mg/$m^3$)')
glue("average_map", fig, display=False)
plt.savefig(op.join(path_figs, 'F15_chlorophyll_mean_map.png'), dpi=300, bbox_inches='tight')
Annual average#
data_y = data_xr.resample(time='1YE').mean()
fig = plot_map_subplots(data_y, dataset_id, shp_eez = shp_eez, cmap = 'Greens', vmin = np.percentile(data_xr.mean(dim = 'time')[dataset_id], 1),
vmax = np.percentile(data_xr.mean(dim = 'time')[dataset_id], 99), cbar = 1)
Annual anomaly#
data_an = data_y - data_xr.mean(dim='time')
fig = plot_map_subplots(data_an, dataset_id, shp_eez = shp_eez, cmap='RdBu_r', vmin=-.1, vmax=.1, cbar = 1)
Average over area#
dict_plot = [{'data' : data_xr.mean(dim = ['longitude', 'latitude']).to_dataframe(),
'var' : dataset_id, 'ax' : 1, 'label' : 'Chlorophyll - MEAN AREA'},]
fig = plot_timeseries_interactive(dict_plot, trendline=True, scatter_dict = None, figsize = (25, 12), label_yaxes = 'Chlorophyll (mg/m3)');
fig.write_html(op.join(path_figs, 'F15_chlorophyll_mean_trend.html'), include_plotlyjs="cdn")
d_p = data_xr.mean(dim = ['longitude', 'latitude']).to_dataframe()
Timeseries at a given point#
loc = [7.37, 134.7]
dict_plot = [{'data' : data_xr.sel(longitude=loc[1], latitude=loc[0], method='nearest').to_dataframe(),
'var' : dataset_id, 'ax' : 1, 'label' : f'Chlorophyll at [{loc[0]}, {loc[1]}]'},]
fig, ax = plot_base_map(shp_eez = shp_eez, figsize = [10, 6])
ax.set_extent([lon_range[0], lon_range[1], lat_range[0], lat_range[1]], crs=ccrs.PlateCarree())
ax.plot(loc[1], loc[0], '*', markersize = 12, color = 'royalblue', transform=ccrs.PlateCarree(), label = 'Location Analysis')
ax.legend()
<matplotlib.legend.Legend at 0x18bd24ec0>
fig = plot_timeseries_interactive(dict_plot, trendline=True, scatter_dict = None, figsize = (25, 12), label_yaxes = 'Chlorophyll (mg/m3)');
ONI index analysis#
p_data = 'https://psl.noaa.gov/data/correlation/oni.data'
df1 = download_oni_index(p_data)
lims = [-.5, .5]
plot_oni_index_th(df1, lims = lims)
df1 = add_oni_cat(df1, lims = lims)
df1['ONI'] = df1['oni_cat']
data_xr['ONI'] = (('time'), df1.iloc[np.intersect1d(data_xr.time, df1.index, return_indices=True)[2]].ONI.values)
data_xr['ONI_cat'] = (('time'), np.where(data_xr.ONI < lims[0], -1, np.where(data_xr.ONI > lims[1], 1, 0)))
data_oni = data_xr.groupby('ONI_cat').mean()
Average#
fig = plot_map_subplots(data_oni, dataset_id, shp_eez = shp_eez, cmap = 'Greens',
vmin = np.percentile(data_xr.mean(dim = 'time')[dataset_id], 1),
vmax = np.percentile(data_xr.mean(dim = 'time')[dataset_id], 99),
sub_plot= [1, 3], figsize = (20, 9), cbar = True, cbar_pad = 0.1,
titles = ['La Niña', 'Neutral', 'El Niño'],)
plt.savefig(op.join(path_figs, 'F15_chlorophyll_ENSO.png'), dpi=300, bbox_inches='tight')
Anomaly#
data_an = data_oni - data_xr.mean(dim='time')
fig = plot_map_subplots(data_an, dataset_id, shp_eez = shp_eez, cmap='RdBu_r', vmin=-.05, vmax=.05,
sub_plot= [1, 3], figsize = (20, 9), cbar = True, cbar_pad = 0.1,
titles = ['La Niña', 'Neutral', 'El Niño'],)
